Thrashing machine



July 22,1930. -w. H. WORTHINGTQN 1,171,240

THRASHING IACHINE Filed Jan. 2l, 1926 2 Sheets-Sheet 1 jizz/@M4021 July22. 1930. w. H. WQRTHINGTQN 1,771,240

THRASHING MACHINE' rma Jan. 21, 192e 2 snets-sheet 2 @mgm 6;@

Patented JulyV 22, 1930 UNITED STATES PATENT OFFICE i WAYNE I-I.WORTHINGTON, OF BATTLE GREEK, MICHIGANfASSIGNOR TO ADVANCE- RUMELYCOMPANY, F LA PORTE, INDIANA, A CORPORATION 0F INDIANA TI'IRASHINGMACHINE Application filed January 21, 1926.' Serial No. 82,874.

My invention relates to a method and apparatus for balancing thereciprocating or vibrating parts of a thrashing machine or grainVseparator. Y

. In the ordinary grain separator there are generally at least twoseparate reciprocating racks or tables. One is that usually termed thegrain pan or grain conveyor, the other as the straw rack. These tworacks are driven from a main crank shaft by pitmen or connecting rodswhich to accommodate other structural parts are .placed in planesinclined one to the other. Owing to the fact that the racks aresupported by swinging links the included angle between the two planes of`these pitmen varies but there is always an average angle between themwhich may be accurately determined.

Experience shows that when ldriven from atwo-way crank shaft with thetwo crankV throws in the same plane7 the two vibrating members or rackswill most of the time be in balance, theywill be out of balance twiceeach revolution during a travel of the crank shaft 'subtended by anYangle substantially equal to the average angle between the two planesof the pitmen and it is this lack of balance of the heavy reciprocatingduring a part of the crank shaft travelwhich sets up the characteristicvibration in a thrashing machine. I have discovered that if instead ofbeing in the same plane the two throws of the crank shaft are in twoplanes inclined to each other at an angle equal to the averageinclination of the planes of the pitmen, the

two racks will always be in balance.

The reason for this is that when the two throws are in the same plane,one of the racks will still be going forward after the other rack haschanged its rearward direction and started forward. When the crankthrowsare offset they can be so set that each rack will reverse its directionof movement' at the same time. Other objects will appear from time totime throughout the specication and claims. Y

My invention is illustrated more or less diagrammatically in theaccompanying drawings, wherein:

\ Figure l isa fragmentary side'elevation showing a thrasher with mydriving mechanism in place;

Figure 2 is a plan view showing the crank shaft;

Figure Sis a vertical cross section on an enlarged scale, taken on line3 3 of-Figure 2;

Figure 4 is a diagram illustrating the conditions ofbalance in a twothrow crank shaft in which the crank pins are 180"` apart and not inbalance;

Figure 5 is a similar view showing the crank pins arranged so as tobalance;

Figure 6 isa diagram showing a threethrow crank shaft in which the partsare in balance. v

Like parts are illustrated by like characters throughout. Y

Where I have referred to a two throw and three throw crank shaft I meana shaft in the first cas'eadapted to operate two pitmen or similardevices, and in the second case adapted to operate three.- Such pitmenmight be in pairs or singly, or the two throw shaft might as shown havefour crank pins operatingin two pairs. Similar conditions might exist inthe crank shaft illustrated in Figure 6.

A is the frame of a thrasher. B is a portion of the housing of athrasher. C is a straw rack and O1 is a'grain pan.

D is a crank shaft having a pair of crank pins D1 D? and. another pairof pins D2 D2. Upon each of the crank pins D1 D1 is mounted one end of apitman D3, the other end of which is pivoted to the straw rack at D,Mounted at one end on each of the pins D2 is a pitman D5, each of whichpivoted at its opposite-end at D6 on the grain pan O1. Y The crank shaftD is carried in bearings D7 supported from a frame A and has at one enda driving pulley D8.

In the diagram shown in Figure t'the crank shaft has a pin X1 and a pinX2. They are placed as shown 180 apart, and the vibrating orreciprocating members of the machine which are driven from these cranksthrough the two pitmen, do not reach the end of their strokessimultaneously. This is a condition which is essential for properbalancing when two such reciprocating members are employed.

A pitman is attached to each of the crank pins at one end and at theother end to a member which is reciprocated. ln the apparatus to whichthepresent application relates generally, the pitmen will be'attachedone to a grain pan and the other to a straw rack, the two being mountedto reciprocate along parallel lines. The length of travel of each of thereciprocated parts is indicated by the lines X3 X3 and X4 Xt.

The line X5 indicates diagrammatically the pitman extending to the upperreciproeating member, and the line X6 indicates similarly the pitmanextending to the lower reciprocated member. As the crank rotates in thedirection of the arrow, the pin X2 moves clockwise, and it is movingawayfrom the member to which its pitman is attached. Thus this member startsits movement to the left from the point shown in the drawing. The memberto which the pitman X6 is attached, which has moved to the right untilit has reached the position shown in full lines in the figure, nowreverses its direction and moves to the left. The member to which thepitman X5 is attached has been moving to the left until the pin reachesthe position shown in full lines. As rotation of the crank continuesthis member does not yet reverse its direction. ft will not reverse itsdirection until the line of the pitmen has crossed the center line oraxis of the crank, then it will reverse its direction and commence tomove to the right. Thus it is obvious that when the crank pins are 180apart the members to which the pitmen are attached do not reverse theirdirection of movement at the same time and there is an interval duringwhich the reciprocated members are moving in the same direction andthere is therefore an interval of imbalance. lt is one of the objects ofthis invention to provide a crank arrangement whereby the movement ofthe reciprocated parts is reversed at the same time so that the twoparts are never moving in the same direction and so that they aretherefore always in a condition of balance; so that for a brief intervalthey are standing still, or changing their direction of movement, orelse movingl in opposite directions. l

In Figure 5 is shown an arrangement of my invention whereby with a twothrow crank shaft two members may be reciprocated in opposite directionsand always in balance. While shall describe this form of the inventionas having a two throw crank shaft and two pitmen, it is obvious thatthis number might be multiplied and there might be a pair of throws andpairs of pitmen or any other such arrangement.

In the form shown in Figure 5 the crank 1 corresponds to the crank X2 ofFigure t, and

the crank 2 corresponds to the crank X1 of that figure. It will benoticed that the crank 2 has been shifted from its location directlyopposite crank 1 so that the angle between the two crank pins 1 and 2 isequal to 180o minus the angle a. This angle a is the angle between themean center line of the pitmen and cranks 1 and 2. The meaning of theeX- pression mean center line77 will be clear from Figure 5 in whichthere is shown at the top of the figure a diagram indicating the lengthof travel of the member to which the pitman, which is attached to crank2, lis attached. Y represents the left limit of the travel, and Y1 theright limit. It will be seen that Y2 is the mean center line of theangle of travel of the pitman which is attached to the crank 2. The lineYS is the mean center line of the angle of travel of the pitman which isattached to the crank 1.

WWhen rotation of the shaft, as shown in Figure 5, takes place in thedirection of the arrow, the pin 1 moving clockwise starts its movementto the left and thus the member to which it is attached commences movingto the left. At the same time the pin 2, moving clockwise has alreadycommenced its movement to the right, although the reciproeating memberto which it is attached has inst reached its extreme left position andis therefore ready to commence its movement t the right, thus the tworeciprocating members reverse their direction. at the same time. Thiswill always take place so that they move in balanced relation.

rlhus the member driven by the pitman attached to crank 2 reaches itsinner or left dead center at the same time that the member driven by thepitman attached to the crank 1 reaches its outer or right dead center.This brings the movement of the reciprocating members driven from cachof the two cranks into phase. rlhe only error between their movementsand the true sinusoidal movement is that due to the angularity of therespective pitmen, due to their having a finite length, and to theshifting of the reciprocating end of the pitmen, due to snch partsheilig mounted on swinging hangers rather than upon surfaces within theplane of the crank shaft axis. It is this latter component of motioncreating, as it does. condition comparable to that in an engine havingoffset connecting rods, which introduces snch kinematic complications asto cause ns to consider the whole system on the basis of mean centerlines of pitmen. rather than upon the inside or outside center lines.

In the form shown in Figure 6 the crank shaft is formed to provide forthree reciprocatingmembers which itis desired to balance by having theirrespective dead centers 120O apart, measured in respect to the crankshaft center. Pitman l is spaced from the mean center line of pitman 3rby the angle a, and pitman 5 is likewise spaced from the mean centerline of pitman 3 by the angle WJ. The order of reciprocation is suchthat crank 3a shall bring its corresponding reciprocating member to theinside or right dead center, followed by crank da and then by crank 5a.The normal spacing of a three throw crank, is that cranks 3, da, and 52Lwill'be equally spaced 120 apart. Due to the angles a and b between theseveral pitman systems, it will be seen that the included angle betweencranks 3a and 4a will be equal to the normal angle (1200) minus theangle a between the mean center line of pitman 3 and the mean centerlino of pitman 4, when meas ured as described above with reference toFigure 5.

ter line of pitman 3 is spaced 240 minus'the angle b, the angulardifference between-the mean center line of pitman 3 and pitman 5.

Although I have shown an operative device, still it will be obvious thatmany changesl might be made in size, shape and arrangement of partswithout departing materially from the spirit of my invention; and Iwish, therefore, that my showing be taken as in a sense diagrammatic.

The use and operation of my invention are as follows:

As shown in the first three figures a four throw crank shaft is used,the throws or crank pins being in pairs. Conditions are those describedand shown in detail in connection with Figure 5.

There are two reciprocating parts, a straw rack and a grain pan. Thesetwo are reciprocated from the crank by means of the pitmen. The balancedcondition described in detail in connection with Figure 5 exists in theform ofthe invention shown in Figures 1 to 3, and the straw rack andgrain pan thus move in the opposite direction and they reverse theirdirection of movement at the same time.

I claim:

1. In a thrasher, a plurality of members mounted for reciprocation andmeans for reciprocating them in balanced relation, said means includinga rotating crank shaft, said shaft so formed that the members allreverse their direction of movement at the same time, said membersmounted one above the other, the axle of the crank shaft beingpositioned below the lowest member.

2. In a thrasher, a plurality of members mounted on different levels forreciprocation and means for reciprocating them in balanced relation,said means including a rotating crank shaft, said shaft so formed thatthe members all reverse their direction of movement at the same time,said members mounted one above the other, the axle of the crank shaftbeing positioned below `the lowest member.

Likewise pitman 5 which would normally be spaced 2400 from the mean een'3. In a thrashing machine a plurality of members mounted on differentlevels for reciprocation, means for reciprocating them and for causingthem to move in balanced relation, including a rotating crank shaft fromwhich they are driven, said shaft provided with a plurality of crankpins or throws, the same being so arranged with relation to each otherthat they cause Vthe members which are driven from them to reverse theirAdirection of movement at the same time, said membersmounted one abovethe other, the axle of the crank shaft being positioned below the lowestmember.

4c. In combination a. plurality of parts separately mounted forreciprocation and means for moving them in balanced relation including arotating crank shaft having a pin or throw for each such part and apitman connecting each such part to its pin, each throw being spacedfrom its adjacent throw a distance equal to 360o divided7 by the totalnumber of throws minus the angle included between the mean center lineof the two adjoining pitmen, said members mounted one above the other,the axle of the crank shaft being positioned below the lowest member.

5. In combination a plurality of parts separately mounted forreciprocation on Adifferent levels and means for moving them in balancedrelation including a rotating crank shaft having a pin'or throw'for eachsuch part Aand a pitman connecting each such part to its pin, each throwbeing spaced from itsY adjacent throw a distancer equal to 360O1dividedby the total number of throws minus the angle included betweenthe meancenter line of the two adjoining pitmen, said members mounted one abovethe other, the axle of the crank shaft being positioned below the lowestmember.

6. In combination a pair of parts separately mounted forreciprocationand means for moving them in balanced relation including a rotatingcrank shaft having a pair of pins or throws and a pitman connecting eachpart with one of such pins, the pins being spaced apart a distance equalto 180D minus the angle included between the mean center line of the twopitmen, said members mounted one above the other, the axle of the crankshaft being positioned below the lowest member.

7. In combination a pair of parts separately mounted for reciprocationon-different levels, and means for moving them in balanced relationincluding a rotating crank shaft having a pair of pins or throws and apitman connecting each part v`with one of such pins, the pins beingspaced apart a distance equal to 180o minus the angle included betweenthe mean center line of the two pitmen, said members mounted one abovethe lli) other, the axle of the crank shaft being positioned below thelowest member.

8. In a. thrasher, a plurality of members mounted for reciprocation andmeans for reciprocating them in balanced relation, said means includinga rotating crank shaft mounted beneath such members, said shaft soformed that the members all reverse their direction 01"' movement at thesame time, said members mounted one above the other, the axle of thecrank shaft being positioned below the lowest member.

9. In a thrasher, a plurality of members mounted on dii'ferent levelsfor reciprocation, and means for reciprocating them in balancedrelation, said means including a rotating crank shaft mounted below suchmembers, said shaft so formed that the members all reverse theirdirection of movement at the same time, said members mounted one abovethe other, the axle of the crank shaft being positioned below the lowestmember.

10. In combination, a pluralityT of members separately mounted :forreciprocating movement on different levels and means for moving all ofthem in balanced relation including a rotary crank shaft ha fing a pinor throw for each such part, and a connecting rod connecting each suchpart to its throw, each crank throw being formed in a plane inclined tothe plane of the adjacent crank throw at an angle equal to the averageinclination of the plane of the connecting rod attached to said crankthrow throughout the several positions of movement of said connectingrod, said members mounted one above the other, the axle of the crankshaft being positioned below the lowest member.

Signed at Battle Creek, county of Calhoun, and State of Michigan, this18th day of January, 1926.

WAYNE H. VORTHINGTON.

